9

CHAPTER 2

REVIEW OF LITERATURE

2.1 GENERAL

This chapter presents the literature reviewed on the self compacting

concrete with fly ash content on various material properties of self

compacting concrete and structural action on concrete structures. A brief

review on the experimental studies of self compacting concrete structures is

presented. They are then followed by the experimental investigation on the

behaviour of beam, column and exterior beam column joints under earthquake

type loading reported in the literature.

2.2 LITERATURE REVIEW ON SELF COMPACTING

CONCRETE

Nan et al. (2001) proposed a new mix design method for self-

compacting concrete in which the amount of aggregates required was

determined and the paste of binders is then filled into the voids of aggregates

to ensure that the concrete thus obtained has flowability, self-compacting

ability and other desired SCC properties. The amount of aggregates, binders

and mixing water as well as type and dosage of superplasticizer to be used are

the major factors influencing the properties of SCC. Slump flow, V-funnel, L-

flow, U-box and compressive strength tests were carried out to examine the

performance of SCC and the results indicate that the proposed method could

produce successfully SCC of high quality.

10

Bouzoubaa and Lachemi (2001) stated that SCC has gained wide

use for placement in congested reinforced concrete structures with difficult

casting conditions. For such applications, the fresh concrete must possess high

fluidity and good cohesiveness. The use of fine materials such as fly ash can

ensure the required concrete properties. The initial results of an experimental

program aimed at producing and evaluating SCC made with high volumes of

fly ash are presented and discussed. The mechanical properties of hardened

concrete such as compressive strength and drying shrinkage were also

determined. The SCCs developed 28-day compressive strengths ranging from

26 to 48 MPa. The results show that an economical SCC could be

successfully developed by incorporating high volumes of class F fly ash. They

concluded that it is possible to design SCC incorporating high volumes of

class F fly ash. The HVFA SCCs have a slump flow in the range of

500-700 mm, a flow time ranging from 3 to 7 seconds, a segregation index

ranging from 0.025 to 0.129 ml/cm2.

Steffen and Walraven (2001) concluded self-compacting concrete

offers several economic and technical benefits by the inclusion of steel fibres

in SCC. Steel fibres bridge the cracks and retard their propagation, and

improve several characteristics and properties of the concrete. Fibres are

known to significantly affect the workability of concrete. Therefore, an

investigation was performed to compare the properties of plain SCC and SCC

reinforced with steel fibres. Two mixtures of SCC with different aggregate

contents were used as reference. Each of the concretes was tested with four

types of steel fibres at different contents in order to answer the question to

what extent the workability of SCC is influenced. The slump flow, a fibre

funnel and the J-ring test were used to evaluate the material characteristics of

the fresh concrete. This paper discussed the suitability of the applied test

methods and the effect of the coarse aggregate content, the content and type

of steel fibres on the workability of SCC.

11

Subramanian and Chattopadhyay (2002) conducted research on an

approximate mix proportion of self-compacting concrete, which would give

the procedure for the selection of a viscosity modifying agent, a compatible

superplasticizer and the determination of their dosages. The Portland cement

was partially replaced with fly ash and blast furnace slag, in the same

percentages as Ozawa has done before. The two researchers have tried to

determine different coarse and fine aggregate contents from those developed

by Okamura. The coarse aggregate content was varied, along with water-

powder (cement, fly ash and slag) ratio, being 50%, 48% and 46% of the solid

volume.

Youjun et al. (2002) in their paper presented the preparation

technology of high strength SCC containing ultrapulverized fly ash (UPFA)

and superplasticizer. After selecting the parameters of mix proportions, a SCC

with good workability, high mechanical properties and high durability was

developed. The experimental results indicate that the fresh mixture has low

slump loss. The compressive strength of concrete reached 80 MPa and the

concrete presents low permeability, good freeze-thaw resistance and low

drying shrinkage. They concluded that

(i) The workability of high-strength SCC with UPFA can be

evaluated by the method combining slump flow and L-box

test.

(ii) The effect of UPFA on fresh concrete is to improve the

viscosity of fresh concrete and its effect is the same as that of

a viscosity agent. It does not decrease the flowability of fresh

concrete.

12

(iii) This SCC with UPFA has higher mechanical properties,

excellent impermeability and freezing resistance and lower

drying shrinkage.

Geiker et al. (2002) conducted test on Torque versus time during

testing of the rheological properties of fresh concrete. The testing was

performed in a BML viscometer and on a self-compacting concrete (w/c =

0.45, 70% rapid hardening Portland cement, 3% silica fume, 27% fly ash,

third generation super plasticizer). He concluded that the relaxation period

needed to obtain steady-state flow may affect the rheological properties

estimated and should be taken into account in the selection of measuring

procedures. Non steady state is likely to cause an overestimation of the plastic

viscosity and an underestimation of the yield value. Furthermore, lack of

steady state may explain the apparent shear-thickening behaviour of self-

compacting concrete reported elsewhere.

Bui et al. (2002) developed a simple apparatus and a rapid method

for testing the segregation resistance of self-compacting concrete (SCC).

Extensive test programs on SCC with differences in water–binder ratios, paste

volumes, combinations between fine and coarse aggregates and different

types as well as different contents of cements and mineral admixtures were

carried out. The test results showed that the developed apparatus and method

are useful in rapidly assessing the segregation resistance of SCC in both

vertical and horizontal directions.

Soylev and Francois (2003) investigated the influence of steel–

concrete interface defects on reinforcing steel corrosion. The defects that were

analyzed in this paper relate to the gaps caused by bleeding, settlement and

segregation of fresh concrete under horizontal reinforcing bars. These defects

are increasing with the concrete depth below the horizontal reinforcement and

depend on the bleeding capacity of concrete mixture. Various concrete

13

mixtures including self-compacting concrete were tested. The defects at the

interface were characterized by the ultimate bond strength recorded in a

pullout test and by the defect length under the reinforcement measured with a

video microscope. The results indicate a good correlation between these two

characterization methods. The corrosion was measured by the resistance of

polarization and corroded surface area. The results allow us to conclude that

the quality of conventional concrete and steel–concrete interface, decreases

with height of concrete section and hence affects directly the corrosion rate.

Bertil (2003) analysed the salt frost scaling and internal frost

resistance of self-compacting concrete that contained increased amount of

filler, different air content and dissimilar methods of casting. The results were

compared with the corresponding properties of normal concrete with the same

water-to-cement ratio (0.39) and air content (6%). The start of the testing was

applied at ages of 28 and 90 days. The strength development of the concrete

was followed in parallel. Six SCC mixes and two NC mixes were studied. The

effects of normal and reversed order of mixing (filler last), increased amount

of filler, fineness of filler, limestone powder, increased air content, and large

hydrostatic concrete pressure were investigated. The results indicated a

substantial improvement of the internal frost resistance of SCC as compared

to NC. The salt frost scaling performed more or less in the same way in SCC

and in NC. No relationship of frost resistance was found to the air-void

structure of the concrete.

Hajime and Masahiro (2003) discussed about mechanism for

achieving self - compactibility, factors of self - compactability in terms of test

results, rational mix design method, new type of superplasticizer suitable for

SCC and segregation-inhibiting agent. They concluded that rational mix

design method and an appropriate acceptance testing method at job site have

both largely been established for SCC.

14

Bertil (2003) studied on sulphate resistance of

self-compacting concrete. For this more than 40 cylinders of concrete were

subjected to a solution with sodium sulphate, sea or distilled water during

900 days. Age at start of testing was either 28 or 90 days. Weight and internal

fundamental frequency were measured. Comparison was done with the

corresponding properties of vibrated concrete. When cured in a solution with

sodium sulphate, the results show larger loss of mass of SCC than that of

vibrated concrete probably due to the limestone filler content in SCC. After

curing in water, sea or distilled, no such weight difference between the curing

types was observed. Internal fundamental frequency did not decrease or differ

between the two types of concrete, i.e. no internal deterioration took place due

to thaumasite sulphate attack during the 900 days of exposure.

Violeta (2003) stated that non pozzolanic fillers are frequently used

to optimise the particle packing and flow behaviour of cementitious paste in

self-compacting concrete (SCC) mixes. He had dealt with the influence of

finely ground limestone and crushed limestone dust on the properties of SCC

mixes in the fresh and hardened state. Mixes were prepared using poorly

graded crushed limestone aggregate. To compensate the lack of fine material

in the crushed sand, a viscosity agent was added to the mixtures. The results

obtained indicate that finer and better-graded limestone dust significantly

increases the deformability of the paste. When a high volume of this filler was

added to the SCC mix, the required self-compacting properties

were achieved at a lower water/ (cement + filler) ratio, and it also appeared

that the addition of filler improves the 28-day compressive strength of

concrete mixes due to the filler effect and improved fine-particle packing.

Hyun et al. (2003) focussed on the rheological design and

modification of the material ingredients for self-consolidation behavior in the

15

fresh state. The rheological design adopts complementary electrosteric

dispersion and stabilization technique to obtain cement pastes with desirable

flow properties at constant particle concentrations dictated by the

micromechanics based design. Such stabilization is realized by optimizing the

dosages of strong polyelectrolyte and non-ionic polymer and by controlling

the mixing procedure of the polymers. The fresh cement paste designed

thereby leads to fresh mortar mix with desirable deformability, cohesiveness,

and high consistency, and thus satisfies the self-consolidating performance of

fresh ECC (Engineered Cementitious Composite) mix. In addition, ductile

strain-hardening performance of the self consolidating ECC is confirmed

through uniaxial tensile test. This ductile composite with excellent fluidity

can be broadly utilized for a variety of applications, e.g. in repair of

deteriorated infrastructures requiring horizontal formworks, or in seismic-

resistant structures with dense reinforcements and requiring high ductility.

Wenzhong and Bartos (2003) have done an experimental study on

permeation properties of a range of different self-compacting concrete mixes

in comparison with those of selected traditional vibrated reference concretes

of the same strength grade. The SCC mixes with characteristic cube strength

of 40 and 60 MPa were designed containing either additional powder as filler

or containing no filler but using a viscosity agent. The results indicated that

the SCC mixes had significantly lower oxygen permeability and sorptivity

than the vibrated normal reference concretes of the same strength grades. The

chloride diffusivity, however, appeared to be much dependent on the type of

filler used; the SCC mixes containing no additional powder but using a

viscosity agent were found to have considerably higher diffusivity than the

reference mixes and the other SCCs.

Corinaldesi and Moriconi (2004) had produced self-compacting

concrete thin precast elements with homogeneously dispersed steel fibres

16

instead of ordinary steel-reinforcing mesh to the concrete mixture at a dosage

of 10% by mass of cement. An adequate concrete strength class was achieved

with a water to cement ratio of 0.40. Compression and flexure tests were

carried out to assess the safety of these thin concrete elements. Moreover,

serviceability aspects were taken into consideration. Firstly, drying shrinkage

tests were carried out in order to evaluate the contribution of steel fibres in

counteracting the high concrete strains due to a low aggregate–cement ratio.

Secondly, the resistance to freezing and thawing cycles was investigated on

concrete specimens in some cases superficially treated with a hydrophobic

agent. Both carbonation and chloride penetration tests were carried out to

assess durability behavior of this concrete mixture.

Manu and Subramanian (2004) discussed the potential for use of SCC in

construction projects that has been effectively demonstrated in several

countries. However, a number of issues need to be addressed further to make

this a widely-acceptable technology. These issues, along with the existing

level of research about various aspects of SCC, including materials and

mixture design, test methods, construction- related issues and properties. Also

they concluded that, use of viscosity modifying agents with high range water

reducing agent for dynamic control of flow and segregation is increasing.

Amit et al. (2004) had described the methodology adopted for the

design of SCC mix, test methods to qualify SCC and method adopted for

concreting of walls and other structures of a condenser of cooling water pump

house at Tarapur Atomic Power Project 3 and 4 and also concluded that SCC

was used for concreting these walls and a few appurtenant structures of a

pump house in Tarapur Atomic Power Project. The placing conditions were

difficult and the reinforcement was congested. The SCC produced with the

water content of 175 l/m3 and a low powder content of 500 kg/m

3 was suitable

for placing in difficult conditions without using external vibration.

17

Bapat et al. (2004) Nuclear Power Corporation of India Ltd.

(NPCIL) intended to develop SCC mixtures, full scale mock ups and actual

use of SCC at the NPP at Kaiga in Karnataka. The authors concluded that an

economical SCC mixture can be developed incorporating low powder and

water contents with fly ash content being as high as 50 percent of the total

powder content and manufactured sand being 70 percent of the total fine

aggregate content, They concluded that it is possible to produce SCC with a

lower water content of 165 kg/m3, a powder content of 450 kg/m3, cement

content of 225 kg/m3

and manufactured sand percentage could be as high as

70 percent of the total fine aggregate content. An economical mix can be

developed with SCC by using as high as 50 percent of fly ash out of the total

powder content.

Pai (2004) discussed the comparison of SCC with control concrete

in proportioning, fresh properties and hardened properties and he made the

cost analysis of SCC and control concrete of approximately 40 MPa strength.

He gave a very promising picture emerging as SCC is comparable in fact

superior to conventional concrete in respect of all properties, preferred when

concreting conditions are difficult. Cost of only the materials of SCC may

appear to be slightly more, say about 15 percent or so. However, on a more

rational basis of the total costs, including the labour charges for formwork and

making good finished surfaces, SCC will be more advantageous. From

holistic considerations, SCC will be more cost-effective.

Lachemi et al. (2004) expressed that self-consolidating concrete

(SCC) is known for its excellent deformability, high resistance to segregation

and use without applying vibration in congested reinforced concrete structures

characterized by difficult casting conditions. The use of viscosity modifying

admixtures (VMA) has proved very effective in stabilizing the rheology of

SCC. Commercial VMAs currently available on the market are costly, which

18

increases the cost of such a concrete. They presented the suitability of four

different types of new polysaccharide-based VMA in the development of

SCC. A preliminary investigation was carried out on the rheological

properties and setting times of mortar mixes with various types and dosages

of VMA to study the influence and suitability of new VMAs. A more detailed

study was then carried out on the SCC fresh and hardened properties such as

slump flow, segregation, bleeding, flow time, setting time and compressive

strength of different mixes with various dosages of an identified new VMA.

The performance of various SCC mixtures with the new VMA was compared

with a SCC using a commercial VMA designated as ‘COM’ and a SCC

mixture with welan gum. The study on new VMA was encouraging and

confirmed the production of satisfactory SCC with acceptable fresh and

hardened properties comparable with or even better than that made with

commercial VMA and welan gum. The suggested mix with 0.05% of the new

Type VMA satisfied the requirement of fresh and hardened properties of SCC

and required 7% less VMA dosage than that required in the commercial VMA

mixture. The SCC with new VMA was also conducted as cost-effective.

Praveen and Kaushik (2004) carried out the studies on the

microstructure of the interfacial transition zone (ITZ) in concrete that governs

its mechanical properties and durability. The two basic differences in SCC

and the conventional concrete are the relatively high water content in SCC

and the presence of extra powdery material like fly ash. They investigated the

ITZ in SCC vis-a-vis conventional concrete on the Scanning Electron

Microscope based study.

(i) Observations using scanning electron microscopy on the

transition zone in samples of SCC reveal a microstructure

distinctly different from that observed in normal concrete.

19

(ii) The presence of microsilica and fly ash particles in the

transition zone densifies and reduces the porosity of this zone

and the transition zone in SCC was free of micro cracks, in

contrast to the normal concrete.

(iii) Distinctive features of the transition zone in SCC lead to the

durability incorporating fly ash and microsilica and hence will

be better than normal concrete.

Poon and Ho (2004) concluded that SCC requires high powder

content or a viscosity agent to increase its segregation resistance. This paper

presented the results of a preliminary study on the utilization of rejected fly

ash (r-FA) as part of powder content. Unsuitable r-FA is used in the

production of blended cements simply due to its coarseness. Preliminary

results suggested that r-FA could be used to replace in the production of SCC

and possibly, with additional benefits. It is technically feasible to utilize r-FA

as part of the powder content in the production of SCC. Besides

environmental benefits, there could be some technical and financial

advantages as well. Further research should cover the influence of r-FA in

improving the segregation resistance of SCC and to evaluate its compatibility

with selected SP.

Mohammed (2004) investigated to develop medium strength SCC.

The cost of materials will be decreased by reducing the cement content and by

using pulverised fuel ash with a minimum amount of superplasticizer. A

factorial design was carried out to mathematically model the influence of five

key parameters on filling and passing abilities, segregation and compressive

strength which are important for the successful development of medium

strength self-compacting concrete incorporating PFA. The parameters

considered in the study were the contents of cement and PFA, water-to-

powder (cement + PFA) ratio (W/P) and dosage of SP. The responses of the

20

derived statistical models are slump flow, fluidity loss, Orimet time, V-funnel

time, L-box, J Ring combined to the Orimet, J Ring combined to cone,

rheological parameters, segregation and compressive strength at 7, 28 and 90

days. Twenty-one mixes were prepared to derive the statistical models, and

five were used for the verification and the accuracy of the developed models.

The models are valid for mixes made with 0.38 to

0.72 W/P, 60 to 216 kg/m3 of cement content, 183 to 317 kg/m3 of PFA and

0% to 1% of SP by mass of powder. The influences of W/P, cement and PFA

contents, and the dosage of SP were characterised and analysed using

polynomial regression, which can identify the primary factors and their

interactions on the measured properties. The results show that MS-SCC can

be achieved with a 28-day compressive strength of 30 to 35 MPa by using up

to 210 kg/m3 of PFA.

Mahesh and Manu (2004) concluded that the slump flow and U-box

test are good qualitative measures of the acceptability of a particular SCC

mixture, while the T 50 slump flow and V-funnel test used to develop

quantitative measures of the flow properties.

Brouwers and Radix (2005) conducted experiments on self

compacting concrete. First, the features of “Japanese and Chinese Methods”

are discussed, in which the packing of sand and gravel were found to play a

major role. Here, the grading and packing of all solids in the concrete mix

serves as a basis for the development of new concrete mixes. Mixes,

consisting of slag blended cement, gravel (4–16 mm), three types of sand

(0–1, 0–2 and 0–4 mm) and a polycarboxylic ether type superplasticizer were

developed. These mixes were extensively tested, both in fresh and hardened

states, and found to meet all practical and technical requirements such as

medium strength and low cost.

21

Soo et al. (2006) concluded that proper selection of test methods

and workability specifications are key concerns in the optimization and

control testing of self consolidating concrete (SCC). Various workability

characteristics were determined for approximately 70 SCC mixtures made

with water-cementitious material ratios (w/cm) of 0.35 and 0.42. Workability

responses included the slump flow, J-Ring, V-funnel flow time, L-box, filling

capacity, and surface settlement tests. Comparisons of various test methods

indicate that the L-box blocking ratio (h2/ h1) and the

J-Ring flow diameter can be related to filling capacity values determined

using the caisson test. It is recommended that SCC used in structural

applications should have slump flow values of 620 to 720 mm. To ensure

proper filling capacity greater than 80%, such concrete should have high

passing ability that corresponds to L-box blocking ratio (h2/ h1) 0.7, J-Ring

flow of 600 to 700 mm, slump flow minus J-Ring flow diameter 50 mm, or

V-funnel flow time 8 seconds. Such SCC should have a settlement rate of

0.16%/h at 30 minutes, corresponding to 0.5% maximum settlement.

Arnaud et al. (2006) investigated on two self-consolidating

concretes (SCCs) and two vibrated concretes (VCs) (25 and 40 MPa

[3625 and 5800 psi]). Different casting conditions were used to study the

effect of the reinforcement orientation (vertical or horizontal) in relation with

the casting direction and the effect of the horizontal bars location along the

height of small and tall concrete elements. In this study, the concrete casting

direction was always vertical. For small-size concrete elements, SCC25

showed a better resistance against bleeding than VC25. The difference,

however, is not significant for SCC40 and VC40. For samples reinforced with

ribbed bars, the orientation of the bars (horizontal or vertical) had a

significant and equivalent influence on both 25 MPa (3625 psi) concretes. The

VC40 and SCC40 bond strength values were almost equivalent and not

affected by the orientation of the bars. For tall concrete elements, voids

22

formation under the horizontal bars was clearly observed for every type of

concrete. The size of the voids was almost equivalent for SCC25, SCC40, and

VC40, but significantly larger in the case of VC25, especially near the top

casting surface. Finally, the maximum ultimate bond strengths obtained were

approximately 20% higher for SCC than for VC, regardless of the concrete

strength.

Reinhardt and Michael (2006) carried out the study on fire

behavior of this specialized SCC of different types with compressive strengths

between 25 and 65 MPa designed, and specimens with an edge length of 300

mm were subjected to fire according to ISO 834 at an age of 180 days. The

compressive strength at 28 days, the weight loss due to drying, the spalling of

the specimens and the residual compressive strength of the concretes after fire

testing were measured and related to the performance of a reference vibrated

concrete.

Aloia et al. (2006) concluded that the use of a Viscosity Enhancing

Admixture (VEA) along with an adequate superplasticizer content enables to

ensure high deformability and stability. However, little is known about the

interactions between superplasticizer and viscosity agent. Hence, we propose

to study several cement pastes formulated from the original paste of a typical

SCC mix. Finally, test results enable to underline the interactions between

superplasticizer and viscosity enhancing admixture used in designing self

compacting concrete.

Burak et al. (2007) studied the adjustment of the water/cement

ratio and superplasticizer dosage as one of the main key properties in

proportioning of SCC mixtures. In their study, five mixtures with different

combinations of water/cement ratio and superplasticizer dosage levels were

23

investigated. Several tests such as slump flow, V-funnel, L-box were carried

out to determine optimum parameters for the self-compactibility of mixtures.

Compressive strength development, modulus of elasticity and splitting tensile

strength of mixtures were also studied. They concluded that optimum

water/cement ratio for producing SCC is in the range of 0.84–1.07 by volume.

The ratios above and below this range may cause blocking or segregation of

the mixture, respectively.

Domone (2007) concluded that the Bond strength of SCC to

reinforcing and prestressing steel is similar to or higher than that of normally

vibrated concrete. Variation of in situ properties in structural elements cast

with SCC is similar to that with NVC and the performance of the structural

elements is largely as predicted by the measured material properties.

Binu et al. (2008) investigated, with large amount of powder

replaced with high volume fly ash based on a rational mix design method

developed by the authors. Because of high fly ash content, essential to study

the development of strength at early ages of curing which may prove to be a

significant factor for the removal of formwork. Rate of gain in strength at

different periods of curing such as 12 h, 18 h, 1 day, 3 days, 7 days, 21 days

and 28 days were studied for various grades of different SCC mixes and

suitable relations have been established for the gain in strength at the early

ages in comparison to the conventional concrete of same grades. Relations

have also been formulated for compressive strength and split tensile strength

for different grades of SCC mixes.

Khatib (2008) has investigated in the influence of fly ash (FA) on

the properties of self-compacting concrete (SCC). Portland cement (PC) was

partially replaced with 0–80% FA. The water to binder ratio was maintained

24

at 0.36 for all mixes. Replacing 40% of PC with FA resulted in a strength of

more than 65 N/mm2at 56 days. High absorption values are obtained with

increasing amount of FA, however, all FA concrete exhibits absorption of less

than 2%. Increasing the admixture content beyond a certain level leads to a

reduction in strength and increase in absorption. The correlation between

strength and absorption indicates that there is sharp decrease in strength as

absorption increases from 1 to 2%.

Dinakar et al. (2008) had done experimental study on the durability

properties of self compacting concretes (SCCs) with high volume

replacements of fly ash. Eight fly ash self compacting concretes of various

strength grades were designed at desired fly ash percentages of 0, 10, 30, 50,

70 and 85%, in comparison with five different mixtures of normal vibrated

concretes (NCs) at equivalent strength grades. The durability properties were

studied through the measurement of permeable voids, water absorption, acid

attack and chloride permeation. The results indicated that the SCCs showed

higher permeable voids and water absorption than the vibrated normal

concretes of the same strength grades. However, in acid attack and chloride

diffusion studies the high volume fly ash SCCs had significantly lower weight

losses and chloride ion diffusion.

Tayyeb et al. (2009) had conducted that to produce low cost SCC,

it is prudent to look at the alternates to help reducing the SSC cost. They

evaluated the usage of bagasse ash as viscosity modifying agent in SCC, and

to study the relative costs of the materials used in SCC. In their research, the

main variables were the proportion of bagasse ash, dosage of superplasticizer

for flowability and water/binder ratio. The parameters kept constant are the

amount of cement and water content. Test results substantiated the feasibility

to develop low cost self compacting concrete using bagasse ash. In the fresh

state of concrete, the different mixes of concrete had slump flow in the range

25

of 333 mm to 815 mm, L-box ratio ranging from 0 to 1 and flow time ranging

from 1.8 s to no flow. Out of twenty five different mixes, five mixes were

found to satisfy the requirements suggested by European federation of

national trade associations representing producers and applicators of specialist

building products (EFNARC) guide for making self compacting concrete. The

compressive strengths developed by the self compacting concrete mixes with

bagasse ash at 28 days were comparable to the control concrete. Cost analysis

showed that the cost of ingredients of specific self compacting concrete mix is

35.63% less than that of control concrete, both having compressive strength

above 34 MPa.

Nicolas et al. (2010) have studied the effect of chemical and

mineral admixtures, including superplasticizer, viscosity modifying agent

(VMA), limestone powder and fly ash in different w/c on fluidity, viscosity,

and stability of self-consolidating mortar. They obtained results which

indicate that w/c is the most significant parameter influencing the rheological

properties of cementitious mixtures, specially their stability. The maximum

allowable w/c for preventing in homogeneity could not be a fixed value for all

the mixtures and should be adjusted for the target fluidity. Using VMAs is an

effective method for stabilizing self-consolidating mortars and preventing any

kinds of instability while limestone powder and fly ash mainly affect bleeding

and aggregate blockage.

Miao (2010) analyzed the self-compacting concrete (SCC) with

levels of up to 80% cement replacement by fly ash in mixes adjusted to give

constant fresh concrete properties. The hardened concrete and the

relationships between hardened properties were then studied. The results

show that SCC with up 80% cement replaced by fly ash is possible. To keep

the filling ability constant, replacement of cement with fly ash would require

an increase in water/powder (W/P) ratio and a reduction in superplasticiser

26

dosage. They also show fly ash have negative effects on passing ability,

consistency retention and hardened concrete properties such as strength. The

comparison between SCC and normally vibrated concrete (NVC) shows that

their material properties of are similar.

2.3 REPORTS OF FLEXURAL BEHAVIOUR ON BEAMS

Mohammed et al. (2003) had studied the structural performance of

full-scale beams (200 300 3800 mm) cast using ordinary concrete and

SCC with two configurations of reinforcement bars. A fibre beam cast with

SCC containing steel fibres was also tested. SCC and ordinary concretes

having standard compressive cube strengths of 35 MPa (Class C35) and 60

MPa (Class C60) for housing and civil engineering applications

respectively, were used to cast a total of eight beams. One beam of each

pair of beams was tested in flexure to determine the load deflection

capacity; the second one provided core samples to determine the uniformity

of the distribution of compressive strength along the length of beams. The

core test results were expressed as estimated in-place cube strength in

accordance with British standard practice and were compared with strengths

obtained from standard cubes cured.

Muthu et al. (2003) presented the results of strength and

deformation behaviour of high strength concrete beams. The beam has been

provided with/without minimum flexural reinforcement specified in

Canadian, Newzealand and Indian standards. A total of eighteen beams were

cast and tested under two point loading. They found the first crack load,

ultimate load, ultimate strain and reserve strength of beams. They concluded

that flexural strength of beam was about one tenth of compressive strength of

concrete, the deflection at ultimate load for high strength concrete beam

occurred at an average value of span/220 and reserve strength beyond

27

cracking load showed a decreasing trend with increase in percentage of

silicafume.

Annie et al. (2004) had done the experimental work to understand

the structural behavior of conventionally vibrated concrete (CVC) and SCC in

hardened stage, reinforced concrete beam of size 150 mm

400 mm 3000 mm with similar concrete strength and identical

reinforcement were cast and tested in flexure. Load at first crack, Load

Carrying Capacity and mode of failure were explained. Also they discussed

the Load-deformation characteristics, Moment-Curvature relationship and

crack spacing, crack widths, number of cracks and crack pattern. They

concluded that the load-deformation behavior of both SCC and CVC beams

were similar up to the peak load stage. Beyond the peak load stage, CVC

beams showed no drop in load with increased deformation. While the peak

and failure loads were nearly the same for CVC beams, the failure load was

nearly 25 percent lower compared to the peak load in SCC beams.

Seshasayi and Reddy (2004) carried out an experimental work to

study the deflection characteristics and ultimate strength capacities in flexure

of high performance concrete beams with and without cement replacement.

Twelve beams were cast and tested. Six beams were of ordinary reinforced

concrete without cement replacement. Other Six beams had cement

replacement of 29 percent (20 percent Fly ash and 9 percent by silicafume).

Replacement of fly ash and silicafume were by equal quantities of weight of

cement. Load-deflection characteristics and the moment carrying capacities of

the two sets of beams were compared. They concluded that behavior in

flexure of concrete with ordinary Portland cement and cement with mineral

admixture will be similar.

28

Hassan et al. (2008) had done an experimental investigation on

shear strength and cracking behavior of full scale beams made with self-

consolidating concrete (SCC) as well as normal concrete (NC). A total of

20 flexural reinforced concrete beams, with no shear reinforcement, were

tested under mid-span concentrated load until shear failure occurred. The

experimental test parameters included concrete type/coarse aggregate content,

beam depth and the longitudinal reinforcing steel ratio. The beam depth

ranged from 150 to 750 mm while the shear span-to-depth ratio (a/d) was kept

constant in all beams. The two longitudinal reinforcing steel ratios used were

1% and 2%. The performance of SCC/NC beams was evaluated based on the

results of crack pattern, crack widths, loads at the first flexure/diagonal

cracking, ultimate shear resistance, and failure modes. The ultimate shear

strength of SCC beams was found to be slightly lower than that of NC beams

and the difference was more pronounced with the reduction of longitudinal

steel reinforcement and with the increase of beam depth. The performance of

code based equations in predicting the shear resistance of SCC/NC beams is

also presented. They concluded that SCC showed similar shear resistance

characteristics in pre-cracking stage as compared with NC. No significant

difference was noted between SCC and NC beam in terms of crack widths,

crack height and crack angles or overall failure mode.

2.4 REPORTS ON BEHAVIOUR OF COLUMNS UNDER AXIAL

LOADS

Fumio et al. (1995) have done a new reinforcing method to improve

the inelastic behavior of reinforced concrete columns. The method combines

the use of high-strength and ordinary strength longitudinal bars. When the

column is subjected to bending moment, the ordinary strength longitudinal

bars yield first and then the high –strength bars yield later in large post-yield

range. Up to the stage of yielding of the high –strength bars, the column does

29

not show significant degradation of load carrying capacity. To confirm the

advantages of the new reinforcing method, flexural analyses on reinforced

concrete columns with different grades of longitudinal bars were conducted.

The results of the analyses indicate that the combined use of different grades

of longitudinal bar improves the inelastic behavior of reinforced concrete

columns.

Shanthi and Sundararajan (2003) have done experimental work on

11 small scale concrete encased build up steel columns under concentric and

eccentric loads. They studied the effects of external compressive load on the

columns, their ultimate strength, failure modes, load-deflection, moment –

curvature and stress-strain. They concluded that failure occurred by crushing

of the concrete at the compression face of the cross section, where the

moment was maximum throughout the test. Hence, concrete encased

composite steel built up columns can be recommended where the loading is

heavy and space saving is of top priority.

Sonebi and Bartos (2003) carried out experimental study on the

structural performance of full scale (300 300 3000 mm) columns cast

using ordinary concrete and self compacting (SCC) concretes with stirrup

configurations representing different degrees of confinement. SCC and

ordinary concrete having compressive strengths of 35 MPa (housing) and

60 MPa (Civil Engineering) were used to cast a total of eight columns. Two

pairs of columns were cast using ordinary concrete and SCC. From each pair

of the reinforced column, one column was tested in uniaxial compression to

determine its load carrying capacity, while the other one was used to take core

samples to determine the distribution of in-situ compressive strength and its

height. The core results were compared to strengths. The in-situ compressive

strengths of SCC were closer to standard cube than those of ordinary

concrete. The distribution of in-situ properties was found to be more uniform

30

in the case of SCC than that of the ordinary concrete. The compressive

strength and the ductility of SCC and the ordinary concrete obtained from the

3m column tests are also compared.

Chien et al. (2004) investigated the behaviour of high- workability

concrete (HWC) columns under concentric compression. Fifteen of the

columns were made with HWC and the rest were made with normal concrete.

The test variables included the concrete strength, amount of longitudinal

reinforcement, volumetric ratio of transverse reinforcement, strength of

transverse reinforcement and the arrangement of transverse reinforcement.

Comparisons were made between HWC columns and normal concrete

columns. The results show that HWC columns have higher stiffness than

normal concrete columns. The ductility and crack control ability of HWC

columns are better than those of normal concrete columns. A decrease of

concrete strength, increase of longitudinal reinforcement, increase of

transverse reinforcement strength and decrease of transverse reinforcement

spacing were found to improve the ductility of confined concrete columns

effectively.

Mohamed et al. (2006) compared the performance of axially loaded

concrete filled steel tube (CFST) columns cast using a conventionally vibrated

normal concrete (NC) and a self-consolidating concrete (SCC) made with a

new viscosity-modifying admixture (VMA). A total of 16 columns

with a standard compressive strength of approximately 50 MPa for both SCC

and NC were tested by applying concentric axial load through the concrete

core. The effect of various parameters such as slenderness ratios, types of

concrete and the addition of longitudinal and hoop reinforcements at different

degrees of confinement was studied. In the service stage, the performance was

judged based on strength, ductility, stress-strain characteristics, degrees of

confinement, load sharing between steel tube and confined concrete and

31

failure modes. Test results showed that the ease of placement and time of

casting were considerably improved for columns with SCC compared to those

with NC. The strength of SCC columns was found comparable to that of their

NC counterparts as the maximum strength enhancement in NC columns

ranged between 1.1 and 7.5% only. The ductility of comparatively shorter

columns with both SCC and NC was similar.

2.5 REPORTS OF EXTERIOR BEAM COLUMN JOINT

Hanson and Connor (1967) had tested seven full size exterior beam

column joints. The principal variables of their study were column size,

column load and degree of confinement in joint. They observed that the

presence of axial load on column improved the behaviour and stressed the

importance of proper detailing of the joint. They emphasized a design

procedure for hoops on supplying adequate confinement and shear resistance

for isolated beam- column joints. It was presented that hoops are not required

for exterior joints confined on at least three sides by beams.

Uzumeri (1977) carried out an experimental study of behaviour of

eight cast in place reinforced concrete beam-column joints subjected to slow

load reversals simulating seismic loading. Variables were the amount and size

of joint reinforcement and stress vs. strain characteristics of joint steel. His

results indicated that the assumption of rigid beam-column joints could give

invalid results. He suggested that the use of joint reinforcement with flat yield

plateau might be undesirable for confinement. He recommended that joint

stirrups should be extended above and below the beam steel at same spacing

as in the joint for a distance of at least half the core dimension to prevent

premature failure in the column just above or below the beam.

Lee et al. (1977) investigated the behaviour of six beam-column

joints designed according to ACI-ASCE committee 352. The design and test

32

variables were the amount of transverse reinforcement, magnitude of axial

load on the column and the severity of loading. They stated that the effect of

column axial load on cracking was that each specimen had cracks in joint and

beam but the cracks were more numerous and severe in specimen without

column axial load. Their results also indicated that there was slightly higher

initial stiffness in specimen with column axial load and lower shear level in

beam due to its larger shear span. They observed that the shear resisted by the

transverse reinforcement increased as the amount of transverse reinforcement

increased.

Ehsani and Wight (1985) investigated the effect of key variables on

the behaviour of external reinforced beam to column connection subjected to

earthquake type loading. The primary variables were the ratio of the column

to beam flexural capacity, the joint shear stresses and the transverse

reinforcement in the joint. They suggested that flexural strength ratio should

be more than 1.4 in order to avoid formation of plastic hinges in the joint.

A significant improvement in the behaviour of a connection was observed if

the joint shear stress was limited to the value recommended by ACI 352R-76.

Their tests indicated that additional transverse reinforcement enhanced the

behaviour of sub assemblage but the construction of such connection was

found to be extremely difficult. They concluded that in case where either the

flexural strength ratio, the joint shear stress or the anchorage requirement

were significantly more conservative than the limit of ACI 352R-76 the

amount of joint transverse reinforcement could be safely reduced.

Abrams (1987) conducted tests on eight small-scale joints, four

medium-scale joints and six large-scale joints. Specimens were subjected to

reversals of lateral force to study scale correlations for nonlinear hysteretic

properties. It was observed that stiffness deterioration was the highest for

small-scale specimens as a result of weaker bond between model

33

reinforcement and mortar. One-quarter scale specimens showed force-

deflection response similar to those of large-scale specimens. He

recommended that minimum usable scale for testing of isolated reinforced

concrete components be one-quarter.

Alameddine and Ehsani (1991) investigated exterior beam to

column connections with high strength concrete with compressive strength of

over 69MPa. The key variables were concrete compressive strength, joint

shear stress and joint transverse reinforcement. They observed that joint

performance was more influenced by the joint shear stress and joint

confinement level than the level of concrete compressive strength. The

increase in joint transverse reinforcement ratio provided additional

confinement for the joint concrete and delayed the deterioration of concrete in

the joint. The improved behaviour of joints with high transverse steel ratio

was less pronounced in specimens with high joint shear stresses. They

emphasized that confinement cannot compensate for the deteriorating effect

of high joint shear stresses.

Tsonos et al. (1992) investigated the improvement in the seismic

behaviour of exterior reinforced concrete beam-column joints resulting from

the presence of inclined reinforcing bars in the joint region. The principal

variables of the testing program were the percentage of inclined reinforcing

bars, the ratio of column moment strength versus beam moment strength and

the horizontal joint shear stress. The exterior beam-column joints with crossed

inclined bars showed high strength and large energy dissipation capacity. The

presence of inclined bars introduced additional new mechanism of shear

transfer. Exterior beam-column joints with inclined bars resisted horizontal

shear stresses higher than the recommendations of the Committee

ACI 352R-85.

34

Kumar et al. (2002) carried out an experimental study to clarify the

effect of joint detailing on the seismic performance of lightly reinforced

concrete frames. The parameters studied were the effect of joint rotation,

column axial load, cross-reinforcement in the joint and percentage of

longitudinal reinforcement in the beam. About eight T-shaped beam to

column joint subassemblies designed and detailed as per IS 13920-1993 were

tested under cyclic loading. They found that use of cross reinforcement in the

joint reduced damage in the joint but also reduced the ductility and energy

dissipation capacity. The test results indicated that presence of axial load in

column and allowing free joint rotation not only increased the strength and

ductility but also reduced the damage in the joint region, they concluded that

ductility and energy dissipation capacity increased with a decrease in the

percentage of longitudinal reinforcement.

Murty et al. (2003) reported the experimental evaluation of

effectiveness of different details of longitudinal beam bar anchorage and

transverse joint reinforcement in exterior beam-column joints of moment

resistant frames. Twelve specimens were tested with four different

arrangements for anchorage of beam longitudinal bars namely Type P, Type

Q, Type R and Type S and three different arrangements of reinforcement in

joint regions namely Type 1, Type 2 and Type 3. Their tests indicated that

among all, the specimens with joint reinforcement Type 2 were the most

effective and that they provided additional strength to the specimens beyond

cracking and reduce the strength deterioration. The Type R specimens (with

full anchorage of longitudinal beam bars) provide the best performance

consisting the strength and ductility of specimens. They concluded that of all

the joint reinforcement detailing schemes investigated, the ACI standard hook

with hairclip-type transverse reinforcement was a preferred combination

because of its ease of construction and overall effectiveness.

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2.6 SUMMARY OF LITERATURE REVIEW

Most of the research literature reviewed, concentrated on

experimental study on the fresh properties of SCC. It is indicated in the

literature that SCC should possess high flowability, high passing ability, high

filling ability and high segregation stability. It is difficult to achieve both high

flowability and high segregation stability at the same time. Another difficulty

is interlocking between the aggregate particles. To improve the cohesiveness

and reduce particle interlocking actions it is good practice to increase powder

content to SCC mixes. Fly ash has been found to improve the mechanical

properties and durability of concrete when used as a cement replacement

material. The literature on beam column joint region indicated the importance

of anchorage through bond strength in the joint region and hence they are

proposed to be investigated in the present study.